> Philosophy and Hypertension :
> If you can't make the connection, perhaps
> the damage has already occurred.
> ------------------------------------------------------------------------
>
> http://health.yahoo.com/alzheimers-causes/blood-pressure-and-the-brai...
> Blood Pressure and the Brain
> Provided by: Psychology Today
>
> The next time a nurse inflates a blood pressure cuff around your
> bicep, pay attention. Those numbers are not just important for your
> heart, but for your brain as well.
>
> It's becoming increasingly clear that high blood pressure, or
> hypertension, is at the root of much cognitive decline that has
> previously been attributed to aging. The more that scientists
> scrutinize brain function, and especially memory, the more they
> conclude that we have the ability to keep our memory and spirit strong
> well into old age. But it depends on how well we nourish our brain
> throughout life.
>
> Hypertension is defined as blood pressure of 140/90 or above. The
> first number is the measurement of the blood's force against artery
> walls when the heart is beating. The second number is the pressure
> between beats. A person is hypertensive if either number is too high.
>
> Most people think salt is the culprit in high blood pressure. In the
> vast majority of hypertensives, salt isn't the root of the problem.
> Only about one third of people with high blood pressure are what
> doctors call "salt sensitive."
>
> "The rest of the folks can eat all the salt they want without seeing
> much change in their blood pressure," says Shari Waldstein, Ph.D.,
> associate professor of psychology at the University of Maryland at
> Baltimore County, who studies the cognitive consequences of
> hypertension. People whose diets are not to blame can pinpoint the
> problem through a trial of medications that target differing pathways
> in the body. Blood pressure is affected by many of the body's systems,
> including kidney function, hormones such as insulin and the
> sympathetic and parasympathetic nervous systems.
>
> Regardless of cause, high blood pressure is extremely dangerous,
> especially for people who don't know they have it, typically people
> who rarely see a doctor. Hypertension has few symptoms; some sufferers
> complain of headaches, nosebleeds or shortness of breath but for the
> most part the body suffers in silence.
>
> High blood pressure does its damage by weakening the blood vessels,
> over time leading the inner lining to slough off. Vessels can be
> weakened to the point that they tear, causing sudden death or
> disability via a stroke or aneurysm. Hypertension can also lead to
> heart attacks.
>
> But long before it creates a health emergency, hypertension takes a
> subtle toll on mental faculties. It can reduce attention, learning,
> memory and decision-making skills in ways that can be clearly seen in
> studies.
>
> "Generally, whatever problems impact cardiovascular health also affect
> cognitive functioning," says Merrill Elias, Ph.D., a professor of
> epidemiology at Boston University who has studied hypertension for 35
> years.
>
> Indeed, some researchers now believe that a substantial amount of
> age-related mental decline has little to do with age and much to do
> with blood pressure. Waldstein says there's a large body of research
> linking hypertension directly to brain function, but scientists don't
> yet know how it causes damage at the cellular level.
>
> Elias says high blood pressure exerts a constant stress on the brain
> and cardiovascular system that appears to be cumulative. "It's more of
> a problem for people who don't go to the doctor," he says. "Just think
> of it as your brain taking a hit every day."
>
> The damage to the brain can come in a variety of forms. In the
> elderly, more than half of whom suffer from hypertension, the damage
> can be detected on MRIs in the form of "white matter lesions." These
> are pinpoint lesions in the brain's message-carrying axons that affect
> cognitive function, especially weakening memory and reasoning and
> significantly impacting quality of life.
>
> High blood pressure can also cause small strokes that may go
> unnoticed, but which diminish the brain's capacity to function. Other
> people who have chronic hypertension actually have small spots on
> their brain where the tissue is dead, says Elias.
>
> But that doesn't mean that high blood pressure is a disease of old
> age. For one thing, many people who are in their 20s and 30s suffer
> from it as well. It's especially important for younger people to
> control their blood pressure so that the damage doesn't start early
> and snowball over time.
>
> But neither is high blood pressure inevitable with age. Blood pressure
> can be kept in check by keeping cholesterol low, not smoking and
> limiting salt. But perhaps the most important factor is keeping
> obesity at bay, a struggle most Americans are not winning.
>
> "Weight is a biggie," says Elias. "The more you weigh, the more
> pressure there is."http://health.yahoo.com/alzheimers-causes/blood-pressure-and-the-brai...